Silva, a popular environmentalist, has surged in the polls
and is threatening to defeat President Dilma Rousseff in the
October elections, unseating Lula's Worker's Party after 12
years in power.

In the video, a cheerful Lula backs the election of
"Marina." But the candidate he is referring to is Marina
Santana, who is seeking a Senate seat for the state of Goiás. In
the false video, Marina Silva's campaign logo has been spliced
in instead.

"This video is a blatant fraud," Workers' Party President
Rui Falcao said at a news conference. Falcao said the party
asked Google, which owns YouTube, to pull the video within 24
hours and identify who posted it.

The Workers' Party is also asking Brazil's electoral court
to open a criminal investigation to find out who was responsible
and plans a civil lawsuit seeking compensatory damages for
harming Lula's image.

Marina Silva's campaign quickly denounced the video as a
fraud and called on the authorities to investigate its origin.

Google said it has not received a court order to remove the
video. The U.S. company added in a statement that YouTube could
be considering its removal if the party used an online reporting
tool for legal complaints.
(Reporting by Anthony Boadle; Editing by Stephen Eisenhammer,
Jonathan Oatis and Cynthia Osterman)